Antlion Pit Construction and Kleptoparasitic Prey
At a site on Archbold Biological Field Station (Lake Placid, Florida), 25% of the diet of antlion larvae (Myrmeleon spp.) consisted of a single species of an ant (Conomyrma sp.); however, in about 10% of antlion pits containing prey, Conomyrma successfully kleptoparasitized, or stole prey from, the antlion. Stolen prey were significantly larger than other prey items. Features that increase the capture efficiency of the pit (steep slope and a layer of fine sand on the walls) are disrupted during the attempted escape of large prey; this decreases the risk of predation by antlions on kleptoparasitic ants. In the laboratory, antlions preferred fine sand over coarse, and moved longer distances when placed on coarse sand. The former behavior will increase prey capture success and reduce the risk of kleptoparasitism. The latter behavior increases the probability of finding a more suitable habitat.